ML060800653
| ML060800653 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 03/24/2006 |
| From: | Bhalchandra Vaidya Plant Licensing Branch III-2 |
| To: | Gerald Williams Entergy Operations |
| vaidya B, NRR/DLPM, 415-3308 | |
| References | |
| TAC MC8180 | |
| Download: ML060800653 (7) | |
Text
March 24, 2006 Mr. George A. Williams Site Vice President Grand Gulf Nuclear Station Entergy Operations, Inc.
P. O. Box 756 Port Gibson, MS 39150
SUBJECT:
GRAND GULF NUCLEAR STATION, UNIT 1 (GGNS), RE: APPLICATION FOR AMENDMENT TO THE FACILITY OPERATING LICENSE (FOL) FOR PROPOSED RESOLUTION OF KAOWOOL ISSUES, REQUEST FOR ADDITIONAL INFORMATION (RAI) (TAC NO. MC8180)
Dear Mr. Williams:
By letter dated August 17, 2005, Entergy Operations, Inc. (the licensee) submitted an amendment request to the FOL for the proposed resolution of Kaowool issues at GGNS.
The NRC staff reviewed the request and determined that additional information is required in order to complete its evaluation. The NRC staff forwarded the draft RAIs to your Matt Crawford, Ron Byrd, and Bill Brice, on February 1, 2006, and forwarded additional draft RAIs to Matt Crawford on February 24, 2006, along with a follow-up RAI on the draft response for RAI question number 1 on February 27, 2006. The above mentioned RAI questions are enclosed.
At the request of Matt Crawford, the NRC staff has made several attempts to schedule a telephone discussion on the proposed responses to the RAIs without success.
In order to complete NRC staff review of GGNSs request by July 1, 2006, please submit the supplemental letter with responses to the RAIs by April 15, 2006.
If you have any questions, please contact me promptly at (301) 415-3308.
Sincerely,
/RA/
Bhalchandra Vaidya, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-416 cc: See next page
Enclosure:
As stated
March 24, 2006 Mr. George A. Williams Site Vice President Grand Gulf Nuclear Station Entergy Operations, Inc.
P. O. Box 756 Port Gibson, MS 39150
SUBJECT:
GRAND GULF NUCLEAR STATION, UNIT 1 (GGNS), RE: APPLICATION FOR AMENDMENT TO THE FACILITY OPERATING LICENSE (FOL) FOR PROPOSED RESOLUTION OF KAOWOOL ISSUES, REQUEST FOR ADDITIONAL INFORMATION (RAI) (TAC NO. MC8180)
Dear Mr. Williams:
By letter dated August 17, 2005, Entergy Operations, Inc. (the licensee) submitted an amendment request to the FOL for the proposed resolution of Kaowool issues at GGNS.
The NRC staff reviewed the request and determined that additional information is required in order to complete its evaluation. The NRC staff forwarded the draft RAIs to your Matt Crawford, Ron Byrd, and Bill Brice, on February 1, 2006, and forwarded additional draft RAIs to Matt Crawford on February 24, 2006, along with a follow-up RAI on the draft response for RAI question number 1 on February 27, 2006. The above mentioned RAI questions are enclosed.
At the request of Matt Crawford, the NRC staff has made several attempts to schedule a telephone discussion on the proposed responses to the RAIs without success.
In order to complete NRC staff review of GGNSs request by July 1, 2006, please submit the supplemental letter with responses to the RAIs by April 15, 2006.
If you have any questions, please contact me promptly at (301) 415-3308.
Sincerely,
/RA/
Bhalchandra Vaidya, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-416 cc: See next page
Enclosure:
As stated DISTRIBUTION:
PUBLIC RidsNrrDorlLplg RidsRgn4MailCenter (KKennedy)
RidsOgcRp LPLIV r/f RidsNrrPMBVaidya RidsAcrsAcnwMailCenter RidsNrrLADJohnson RidsNrrDorlDpr SWeerakkody ACCESSION NO: ML060800653
- No substantial change from RAI Memo OFFICE LPL4/PM LPL4/LA AFPB/BC
- LPL4/BC NAME BVaidya DJohnson SWeerakkody DTerao DATE 03 / 23/2006 03 / 23/2006 02/16/2006 03 / 24/2006 OFFICIAL RECORD COPY
Enclosure Page 1 of 3 GRAND GULF NUCLEAR STATION, UNIT 1 APPLICATION FOR AMENDMENT TO THE FACILITIES OPERATING LICENSE REGARDING PROPOSED RESOLUTION OF KAOWOOL ISSUES TAC NO. MC8180 REQUESTS FOR ADDITIONAL INFORMATION RAI-1. In Section 4.2.3.3 on PSA [Probabilistic Safety Assessment] Quality, the licensee states that... [R]evision [2] of the [GGNS] PSA addressed most of the important observations resulting from the peer review and updated various elements of the analysis. This internal events model was used along with the detailed fire scenario and cable routing information from the GGNS Fire IPEEE [Individual Plant Examination of External Events]
analysis to develop an updated Fire PSA model that was used in the risk calculations for this analysis. Since the preceding seems to imply that, while most of the important observations from the peer review had been addressed prior to using the updated internal events model for this analysis, some important observations still remain to be addressed. Please provide a list of these remaining important observations and discuss if failure to have addressed them in any way affects the results of this analysis. If there are any effects, how have they been accounted/compensated for in this analysis?
RAI-2. In Section 4.2.3.1 on Core Damage Frequency (CDF) and the Risk Analysis portion of, the licensee states that [t]he transient fire frequency for each scenario is weighted based on the area that a fire must be in to result in damage to a given division
... [a]ccording to the Inspection Manual Chapter 0609, Appendix F [Fire Protection Significance Determination Process (FPSDP)]. Has the licensee performed an alternate evaluation for transient fire frequency, including weighting, using the more detailed reference which is the basis for the FPSDP, namely NUREG/CR-6850 (Electrical Power Research Institute (EPRI) Topical Report (TR)-1011989), EPRI/NRC-RES [Office of Nuclear Regulatory Research] Fire PRA [Prababilistic Risk Assessment]
Methodology for Nuclear Power Facilities? In Volume 2, Chapter 6, of this reference, both a different transient fire frequency and weighting scheme are recommended. A comparison between the results from the licensees Fire Protection Significance Determination Process (FPSDP)-based estimates and those using NUREG/CR-6850 should be provided, at least for sensitivity purposes.
RAI-3. The table Determination of CDF on page 24 of Attachment 3, Change Analysis, lists the Conditional Core Damage Probability (CCDP) for Scenario 316, Non-failed Division 2, as 1.62E-03. Table 3-12, Refined Results of Fire PRA, on page 19 of Enclosure 2, Grand Gulf [Nuclear Station] Fire PRA Quantitative Refinements, lists this same CCDP as 1.62E-04. Please correct whichever table is in error.
RAI-4. Fire modeling analysis of cable interactions in the auxiliary building is based on thermoset cables. In a situation where cables are mixed in a cable tray, this would allow
Enclosure Page 2 of 3 a lower threshold for failure and ignition of thermoplastic cables. Thermoplastic cables can provide a path for ignition of adjacent thermoset cables. Are there any situations with mixed cable types in a tray? What failure temperature was used in the fire modeling to damage redundant cables?
RAI-5. Fire modeling results will always have a level of uncertainty. Uncertainties in the predications of fire models arise from modeling simplifications employed by an analyst or are inherent to the modeling tools used due to a lack of knowledge concerning the values of key model parameters. Discuss uncertainties associated with the fire modeling results presented in the evaluation.
RAI-6. The column line labeling on the various drawings is difficult to read, which inhibits cross referencing with the Background Section (pp. 7-13) of the submittal. Verify that each fire scenario presented is protected by an automatic suppression system and an automatic detection system. Are the fire areas under consideration protected throughout by automatic suppression and detection? Note any other defense-in-depth measures present for each fire scenario.
RAI-7. The section Fire Scenarios on pages 16 and 17 of Attachment 3, Change Analysis, describes two different types of miscellaneous fuel packages: trash bags and Class A combustibles. The trash bags have unit heat release rates (kW/m2) between 1.5 and 4 times that of the Class A combustibles, based on orientation. Provide a more specific reference for the unit heat release rate for the Class A material. Discuss the difference in unit heat release rates between the miscellaneous Class A fuel packages in the combustible storage areas and the trash bags assumed to be located in the combustible exclusion zones. Are any of the trash bags ever expected to be located in the combustible storage areas? What effect would this have on the fire scenarios presented?
RAI-8. Describe the material composition of the trash collection bins referenced in the section Fire Scenarios on page 16 of Attachment 3, Change Analysis. If the collection bins are made from combustible material, discuss their effect on the appropriate fire scenarios.
RAI-9. On page 21 of the section CDF of Attachment 3, Change Analysis, the assumption is made that the plausible floor area used in the calculation of the Weighting Factor for Transient Fires is equal to 50% of the total floor area. This assumption is characterized as conservative. Estimate the actual plausible area in each of the fire zones.
RAI-10 : Follow-up Question based on the review of Draft Response to RAI Question 1 Are the unresolved deficiencies, cited as not appearing in or affecting the fire PRA, of a purely calculational nature such that (1) these initiators CANNOT be induced by fire, or (2) even if they could be induced by fire, the calculational deficiency would not carry over into the resulting accident sequence (i.e., event/fault trees)? For example, referencing the Facts and Observations (F&O) for Element AS-7, if a fire induced a T3B event and fire water was being used to suppress the fire, would there be some limit on the fire water's ability to also provide low pressure makeup to the Reactor Pressure
Enclosure Page 3 of 3 Vessel (RPV)? If so, is this degradation of the fire water capability (if any) reflected in the fire CDF for a T3B fire-induced initiating event?
The response must ensure that, although the affected events cited in the F&O's are not fire initiators or fire-related failures, they CANNOT be induced or affected by fire-related failures that, on the surface, would appear to be totally unrelated but, under the surface, somehow could be connected (as discussed in the example for AS-7).
November 2005 Grand Gulf Nuclear Station cc:
Executive Vice President
& Chief Operating Officer Entergy Operations, Inc.
P. O. Box 31995 Jackson, MS 39286-1995 Wise, Carter, Child & Caraway P. O. Box 651 Jackson, MS 39205 Winston & Strawn 1700 K Street, N.W.
Washington, DC 20006-3817 Chief Energy and Transportation Branch Environmental Compliance and Enforcement Division Mississippi Department of Environmental Quality P. O. Box 10385 Jackson, MS 39289-0385 President Claiborne County Board of Supervisors P. O. Box 339 Port Gibson, MS 39150 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 399 Port Gibson, MS 39150 General Manager, GGNS Entergy Operations, Inc.
P. O. Box 756 Port Gibson, MS 39150 Attorney General Department of Justice State of Louisiana P. O. Box 94005 Baton Rouge, LA 70804-9005 State Health Officer State Board of Health P. O. Box 139 Jackson, MS 39205 Office of the Governor State of Mississippi Jackson, MS 39201 Attorney General Asst. Attorney General State of Mississippi P. O. Box 220 Jackson, MS 39205 Vice President, Operations Support Entergy Operations, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Director Nuclear Safety Assurance Entergy Operations, Inc.
P. O. Box 756 Port Gibson, MS 39150 Director Nuclear Safety & Licensing Entergy Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213-8298